<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../vue.js"></script>
</head>

<body>
  <div id="app">
    <button @click="isSagili = !isSagili">改变人物</button>
    <h1>我喜欢的是:{{isSagili?"和泉纱雾":"五条悟"}}</h1>
    <img :src="url" alt="">
  </div>
  <script>
    Vue.config.productionTip = false;

    const vm = new Vue({
      el: "#app",
      data() {
        return {
          isSagili: true,
          url: "../img/桌面5.jpg"
        }
      },
      //watch配置项
      watch: {
        //监听isHot属性
        isSagili: {
          //当被监听的isHot发生改变的时候,handler函数就会执行
          handler(newValue, oldValue) {
            //当不需要第二个参数的时候可以不传
            console.log("handler", newValue, oldValue);

            //根据当前的值 去修改url的地址
            // newValue ? this.url = "./re.webp" : this.url = "./leng.gif"
            this.url = newValue ? "../img/桌面5.jpg" : "../img/桌面4.jpg"
          }
        }
      }
    })
  </script>
</body>

</html>